Please move a document #18

johnbent · 2020-09-01T21:23:02Z

Can you please move https://github.com/Seagate/cortx/blob/main/doc/be/motr-in-prose.md into the cortx-motr repo? This will entail two PR's. First please use a PR to cortx-motr to add it there. After that is done, then please remove it from the existing location and update the link to it here: https://github.com/Seagate/cortx/blob/main/doc/architecture.md.

Thanks,

John

VenkyOS · 2020-09-02T04:23:41Z

Hi John,

I will do the same and raise a PR as required.

Regards,
Venky

stale · 2020-09-09T12:38:04Z

This issue/pull request has been marked as needs attention as it has been left pending without new activity for 4 days. Tagging @huanghua78 @mukundkanekar for appropriate assignment. Sorry for the delay & Thank you for contributing to CORTX. We will get back to you as soon as possible.

VenkyOS · 2020-09-22T12:11:12Z

This issue has been resolved. It can be closed.

Currently be seg size MOTR_M0D_IOS_BESEG_SIZE from /etc/sysconfig/motr not being used and default value of 8GB is used due to a bug in motr-server script, which checks for "^ios" regex in systemd unit file, which is no longer used with hare based cluster. The following crash is observed, #3 0x00007fca296780b4 in m0_panic (ctx=ctx@entry=0x7fca29a72020 <__pctx.8247>) at lib/assert.c:52 #4 0x00007fca295bdf20 in mem_alloc (zonemask=2, size=<optimized out>, tx=0x7fc84c2266b8, btree=0x40000015f210) at be/btree.c:127 #5 btree_save (tree=tree@entry=0x40000015f210, tx=tx@entry=0x7fc84c2266b8, op=op@entry=0x7fc92bffe460, key=key@entry=0x7fc92bffe6d0, val=val@entry=0x7fc92bffe6e0, anchor=anchor@entry=0x0, optype=optype@entry=BTREE_SAVE_INSERT, zonemask=zonemask@entry=2) at be/btree.c:1453 #6 0x00007fca295bdfe8 in be_btree_insert (tree=tree@entry=0x40000015f210, tx=tx@entry=0x7fc84c2266b8, op=op@entry=0x7fc92bffe460, key=key@entry=0x7fc92bffe6d0, val=val@entry=0x7fc92bffe6e0, anchor=anchor@entry=0x0, zonemask=zonemask@entry=2) at be/btree.c:1907 #7 0x00007fca295bf018 in m0_be_btree_insert (tree=tree@entry=0x40000015f210, tx=tx@entry=0x7fc84c2266b8, op=op@entry=0x7fc92bffe460, key=key@entry=0x7fc92bffe6d0, val=val@entry=0x7fc92bffe6e0) at be/btree.c:1938 #8 0x00007fca295f7931 in cob_table_insert (tree=0x40000015f210, tx=tx@entry=0x7fc84c2266b8, key=key@entry=0x7fc92bffe6d0, val=val@entry=0x7fc92bffe6e0) at cob/cob.c:721 #9 0x00007fca295fa5cf in m0_cob_name_add (cob=cob@entry=0x7fc9241ffc50, nskey=nskey@entry=0x7fc9241ffdc0, nsrec=nsrec@entry=0x7fc92bffe8e0, tx=tx@entry=0x7fc84c2266b8) at cob/cob.c:1640 #10 0x00007fca295fa85a in m0_cob_create (cob=0x7fc9241ffc50, nskey=0x7fc9241ffdc0, nsrec=nsrec@entry=0x7fc92bffe8e0, fabrec=fabrec@entry=0x0, omgrec=omgrec@entry=0x0, tx=tx@entry=0x7fc84c2266b8) at cob/cob.c:1428 #11 0x00007fca2966b097 in m0_cc_cob_setup (cc=cc@entry=0x7fc84c2265d0, cdom=<optimized out>, attr=attr@entry=0x7fc92bffec20, ctx=ctx@entry=0x7fc84c2266b8) at ioservice/cob_foms.c:1058 #12 0x00007fca2966b275 in cc_cob_create (attr=0x7fc92bffec20, cc=0x7fc84c2265d0, fom=0x7fc84c2265f0) at ioservice/cob_foms.c:1016 #13 cob_stob_create (fom=fom@entry=0x7fc84c2265f0, attr=attr@entry=0x7fc92bffec20) at ioservice/cob_foms.c:517 #14 0x00007fca2966c40b in cob_ops_fom_tick (fom=0x7fc84c2265f0) at ioservice/cob_foms.c:767 #15 0x00007fca2964c24b in fom_exec (fom=0x7fc84c2265f0) at fop/fom.c:785 #16 loc_handler_thread (th=0x1b5c1e0) at fop/fom.c:925 #17 0x00007fca2967e50e in m0_thread_trampoline (arg=arg@entry=0x1b5c1e8) at lib/thread.c:117 #18 0x00007fca2968875d in uthread_trampoline (arg=0x1b5c1e8) at lib/user_space/uthread.c:98 #19 0x00007fca28e36ea5 in start_thread () from /lib64/libpthread.so.0 #20 0x00007fca27f278cd in clone () from /lib64/libc.so.6 So for LDR R1, as LVM paths are passed only for ioservices, at the same place be seg size is applied. Signed-off-by: Madhavrao Vemuri <madhav.vemuri@seagate.com>

It was possible for the op, passed to m0_be_io_sched_add(), to become DONE before sched lock is taken in be_io_sched_cb() because parent op could become DONE before the child op M0_BTS_GC callback is called. This situation led to failed invariant, assertion failures [1] or just spinning in infinite loop in m0_list invariant due to a broken list [2]. The patch fixes the issue by moving the op (passed to m0_be_io_sched_add()) to DONE only after finishing processing of the corresponding m0_be_io. The bug was discovered during EOS-25005 patch testing. [1] be-ut io_sched motr[15961]: e4b0 FATAL [lib/assert.c:50:m0_panic] panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() (be/io_sched.c:132) [git: 2.0.0-307-37-gd35074f6-dirty] /w/var/m0ut/m0trace.15961 Motr panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() be/io_sched.c:132 (errno: 0) (last failed: none) [git: 2.0.0-307-37-gd35074f6-dirty] pid: 15961 /w/var/m0ut/m0trace.15961 ... [2] (gdb) bt #0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135 #1 0x00007f432af53e1b in _L_lock_812 () from /lib64/libpthread.so.0 #2 0x00007f432af53ce8 in __GI___pthread_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at ../nptl/pthread_mutex_lock.c:79 #3 0x00007f432b8c3520 in m0_arch_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/user_space/umutex.c:56 #4 0x00007f432b8aee6f in m0_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/mutex.c:55 #5 0x00007f432b76673b in m0_be_io_sched_lock (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>) at be/io_sched.c:72 #6 0x00007f432b766a75 in be_io_sched_cb (op=0x7f4288000998, param=0x7f42880008c0) at be/io_sched.c:123 #7 0x00007f432b771bb3 in be_op_done (op=0x7f4288000998) at be/op.c:257 #8 0x00007f432b771cb6 in m0_be_op_done (op=0x7f4288000998) at be/op.c:276 #9 0x00007f432b765715 in be_io_finished (bio=0x7f42880008c0) at be/io.c:555 #10 0x00007f432b7658e1 in be_io_cb (link=0x7f4288001040) at be/io.c:587 #11 0x00007f432b8a53a0 in clink_signal (clink=0x7f4288001040) at lib/chan.c:135 #12 0x00007f432b8a54ff in chan_signal_nr (chan=0x7f4288000f38, nr=0) at lib/chan.c:154 #13 0x00007f432b8a55d4 in m0_chan_broadcast (chan=0x7f4288000f38) at lib/chan.c:174 #14 0x00007f432b8a55fa in m0_chan_broadcast_lock (chan=0x7f4288000f38) at lib/chan.c:181 #15 0x00007f432ba03cfe in ioq_complete (ioq=0x1367bc0, qev=0x7f42886a3fe0, res=8, res2=0) at stob/ioq.c:587 #16 0x00007f432ba041d1 in stob_ioq_thread (ioq=0x1367bc0) at stob/ioq.c:669 #17 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x1367be0) at lib/thread.c:117 #18 0x00007f432b8c37fc in uthread_trampoline (arg=0x1367be0) at lib/user_space/uthread.c:98 #19 0x00007f432af51e25 in start_thread (arg=0x7f42ccff9700) at pthread_create.c:308 #20 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 (gdb) thread 2 [Switching to thread 2 (Thread 0x7f428ffff700 (LWP 8730))] #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 253 if (!M0_CHECK_EX(m0_tlink_invariant(d, amb(d, scan)))) (gdb) bt #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 #1 0x00007f432b8b1f13 in m0_tlist_add (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, obj=0x7f42880008c0) at lib/tlist.c:128 #2 0x00007f432b7664c8 in sched_io_tlist_add (list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, amb=0x7f42880008c0) at be/io_sched.c:48 #3 0x00007f432b766d88 in be_io_sched_insert (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0) at be/io_sched.c:161 #4 0x00007f432b767144 in m0_be_io_sched_add (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0, ext=0x7f428fffed00, op=0x7f4288000c00) at be/io_sched.c:193 #5 0x00007f432cf8a008 in be_ut_io_sched_thread (param=0x136a2b0) at be/ut/io_sched.c:241 #6 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x136bad0) at lib/thread.c:117 #7 0x00007f432b8c37fc in uthread_trampoline (arg=0x136bad0) at lib/user_space/uthread.c:98 #8 0x00007f432af51e25 in start_thread (arg=0x7f428ffff700) at pthread_create.c:308 #9 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

It was possible for the op, passed to m0_be_io_sched_add(), to become DONE before sched lock is taken in be_io_sched_cb() because parent op could become DONE before the child op M0_BTS_GC callback is called. This situation led to failed invariant, assertion failures [2] or just spinning in infinite loop in m0_list invariant due to a broken list [3]. The patch fixes the issue by moving the op (passed to m0_be_io_sched_add()) to DONE only after finishing processing of the corresponding m0_be_io. [1] be-ut io_sched motr[15961]: e4b0 FATAL [lib/assert.c:50:m0_panic] panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() (be/io_sched.c:132) [git: 2.0.0-307-37-gd35074f6-dirty] /w/var/m0ut/m0trace.15961 Motr panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() be/io_sched.c:132 (errno: 0) (last failed: none) [git: 2.0.0-307-37-gd35074f6-dirty] pid: 15961 /w/var/m0ut/m0trace.15961 ... [2] (gdb) bt #0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135 #1 0x00007f432af53e1b in _L_lock_812 () from /lib64/libpthread.so.0 #2 0x00007f432af53ce8 in __GI___pthread_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at ../nptl/pthread_mutex_lock.c:79 #3 0x00007f432b8c3520 in m0_arch_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/user_space/umutex.c:56 #4 0x00007f432b8aee6f in m0_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/mutex.c:55 #5 0x00007f432b76673b in m0_be_io_sched_lock (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>) at be/io_sched.c:72 #6 0x00007f432b766a75 in be_io_sched_cb (op=0x7f4288000998, param=0x7f42880008c0) at be/io_sched.c:123 #7 0x00007f432b771bb3 in be_op_done (op=0x7f4288000998) at be/op.c:257 #8 0x00007f432b771cb6 in m0_be_op_done (op=0x7f4288000998) at be/op.c:276 #9 0x00007f432b765715 in be_io_finished (bio=0x7f42880008c0) at be/io.c:555 #10 0x00007f432b7658e1 in be_io_cb (link=0x7f4288001040) at be/io.c:587 #11 0x00007f432b8a53a0 in clink_signal (clink=0x7f4288001040) at lib/chan.c:135 #12 0x00007f432b8a54ff in chan_signal_nr (chan=0x7f4288000f38, nr=0) at lib/chan.c:154 #13 0x00007f432b8a55d4 in m0_chan_broadcast (chan=0x7f4288000f38) at lib/chan.c:174 #14 0x00007f432b8a55fa in m0_chan_broadcast_lock (chan=0x7f4288000f38) at lib/chan.c:181 #15 0x00007f432ba03cfe in ioq_complete (ioq=0x1367bc0, qev=0x7f42886a3fe0, res=8, res2=0) at stob/ioq.c:587 #16 0x00007f432ba041d1 in stob_ioq_thread (ioq=0x1367bc0) at stob/ioq.c:669 #17 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x1367be0) at lib/thread.c:117 #18 0x00007f432b8c37fc in uthread_trampoline (arg=0x1367be0) at lib/user_space/uthread.c:98 #19 0x00007f432af51e25 in start_thread (arg=0x7f42ccff9700) at pthread_create.c:308 #20 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 (gdb) thread 2 [Switching to thread 2 (Thread 0x7f428ffff700 (LWP 8730))] #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 253 if (!M0_CHECK_EX(m0_tlink_invariant(d, amb(d, scan)))) (gdb) bt #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 #1 0x00007f432b8b1f13 in m0_tlist_add (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, obj=0x7f42880008c0) at lib/tlist.c:128 #2 0x00007f432b7664c8 in sched_io_tlist_add (list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, amb=0x7f42880008c0) at be/io_sched.c:48 #3 0x00007f432b766d88 in be_io_sched_insert (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0) at be/io_sched.c:161 #4 0x00007f432b767144 in m0_be_io_sched_add (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0, ext=0x7f428fffed00, op=0x7f4288000c00) at be/io_sched.c:193 #5 0x00007f432cf8a008 in be_ut_io_sched_thread (param=0x136a2b0) at be/ut/io_sched.c:241 #6 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x136bad0) at lib/thread.c:117 #7 0x00007f432b8c37fc in uthread_trampoline (arg=0x136bad0) at lib/user_space/uthread.c:98 #8 0x00007f432af51e25 in start_thread (arg=0x7f428ffff700) at pthread_create.c:308 #9 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113

It was possible for the op, passed to m0_be_io_sched_add(), to become DONE before sched lock is taken in be_io_sched_cb() because parent op could become DONE before the child op M0_BTS_GC callback is called. This situation led to failed invariant, assertion failures [1] or just spinning in infinite loop in m0_list invariant due to a broken list [2]. The patch fixes the issue by moving the op (passed to m0_be_io_sched_add()) to DONE only after finishing processing of the corresponding m0_be_io. The bug was discovered during EOS-25005 patch testing. [1] be-ut io_sched motr[15961]: e4b0 FATAL [lib/assert.c:50:m0_panic] panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() (be/io_sched.c:132) [git: 2.0.0-307-37-gd35074f6-dirty] /w/var/m0ut/m0trace.15961 Motr panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() be/io_sched.c:132 (errno: 0) (last failed: none) [git: 2.0.0-307-37-gd35074f6-dirty] pid: 15961 /w/var/m0ut/m0trace.15961 ... [2] (gdb) bt #0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135 #1 0x00007f432af53e1b in _L_lock_812 () from /lib64/libpthread.so.0 #2 0x00007f432af53ce8 in __GI___pthread_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at ../nptl/pthread_mutex_lock.c:79 #3 0x00007f432b8c3520 in m0_arch_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/user_space/umutex.c:56 #4 0x00007f432b8aee6f in m0_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/mutex.c:55 #5 0x00007f432b76673b in m0_be_io_sched_lock (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>) at be/io_sched.c:72 #6 0x00007f432b766a75 in be_io_sched_cb (op=0x7f4288000998, param=0x7f42880008c0) at be/io_sched.c:123 #7 0x00007f432b771bb3 in be_op_done (op=0x7f4288000998) at be/op.c:257 #8 0x00007f432b771cb6 in m0_be_op_done (op=0x7f4288000998) at be/op.c:276 #9 0x00007f432b765715 in be_io_finished (bio=0x7f42880008c0) at be/io.c:555 #10 0x00007f432b7658e1 in be_io_cb (link=0x7f4288001040) at be/io.c:587 #11 0x00007f432b8a53a0 in clink_signal (clink=0x7f4288001040) at lib/chan.c:135 #12 0x00007f432b8a54ff in chan_signal_nr (chan=0x7f4288000f38, nr=0) at lib/chan.c:154 #13 0x00007f432b8a55d4 in m0_chan_broadcast (chan=0x7f4288000f38) at lib/chan.c:174 #14 0x00007f432b8a55fa in m0_chan_broadcast_lock (chan=0x7f4288000f38) at lib/chan.c:181 #15 0x00007f432ba03cfe in ioq_complete (ioq=0x1367bc0, qev=0x7f42886a3fe0, res=8, res2=0) at stob/ioq.c:587 #16 0x00007f432ba041d1 in stob_ioq_thread (ioq=0x1367bc0) at stob/ioq.c:669 #17 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x1367be0) at lib/thread.c:117 #18 0x00007f432b8c37fc in uthread_trampoline (arg=0x1367be0) at lib/user_space/uthread.c:98 #19 0x00007f432af51e25 in start_thread (arg=0x7f42ccff9700) at pthread_create.c:308 #20 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 (gdb) thread 2 [Switching to thread 2 (Thread 0x7f428ffff700 (LWP 8730))] #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 253 if (!M0_CHECK_EX(m0_tlink_invariant(d, amb(d, scan)))) (gdb) bt #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 #1 0x00007f432b8b1f13 in m0_tlist_add (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, obj=0x7f42880008c0) at lib/tlist.c:128 #2 0x00007f432b7664c8 in sched_io_tlist_add (list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, amb=0x7f42880008c0) at be/io_sched.c:48 #3 0x00007f432b766d88 in be_io_sched_insert (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0) at be/io_sched.c:161 #4 0x00007f432b767144 in m0_be_io_sched_add (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0, ext=0x7f428fffed00, op=0x7f4288000c00) at be/io_sched.c:193 #5 0x00007f432cf8a008 in be_ut_io_sched_thread (param=0x136a2b0) at be/ut/io_sched.c:241 #6 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x136bad0) at lib/thread.c:117 #7 0x00007f432b8c37fc in uthread_trampoline (arg=0x136bad0) at lib/user_space/uthread.c:98 #8 0x00007f432af51e25 in start_thread (arg=0x7f428ffff700) at pthread_create.c:308 #9 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 Signed-off-by: Maksym Medvied <maksym.medvied@seagate.com>

It was possible for the op, passed to m0_be_io_sched_add(), to become DONE before sched lock is taken in be_io_sched_cb() because parent op could become DONE before the child op M0_BTS_GC callback is called. This situation led to failed invariant, assertion failures [1] or just spinning in infinite loop in m0_list invariant due to a broken list [2]. The patch fixes the issue by moving the op (passed to m0_be_io_sched_add()) to DONE only after finishing processing of the corresponding m0_be_io. The bug was discovered during EOS-25005 patch testing. [1] be-ut io_sched motr[15961]: e4b0 FATAL [lib/assert.c:50:m0_panic] panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() (be/io_sched.c:132) [git: 2.0.0-307-37-gd35074f6-dirty] /w/var/m0ut/m0trace.15961 Motr panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() be/io_sched.c:132 (errno: 0) (last failed: none) [git: 2.0.0-307-37-gd35074f6-dirty] pid: 15961 /w/var/m0ut/m0trace.15961 ... [2] (gdb) bt #0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135 Seagate#1 0x00007f432af53e1b in _L_lock_812 () from /lib64/libpthread.so.0 Seagate#2 0x00007f432af53ce8 in __GI___pthread_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at ../nptl/pthread_mutex_lock.c:79 Seagate#3 0x00007f432b8c3520 in m0_arch_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/user_space/umutex.c:56 Seagate#4 0x00007f432b8aee6f in m0_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/mutex.c:55 Seagate#5 0x00007f432b76673b in m0_be_io_sched_lock (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>) at be/io_sched.c:72 Seagate#6 0x00007f432b766a75 in be_io_sched_cb (op=0x7f4288000998, param=0x7f42880008c0) at be/io_sched.c:123 Seagate#7 0x00007f432b771bb3 in be_op_done (op=0x7f4288000998) at be/op.c:257 Seagate#8 0x00007f432b771cb6 in m0_be_op_done (op=0x7f4288000998) at be/op.c:276 Seagate#9 0x00007f432b765715 in be_io_finished (bio=0x7f42880008c0) at be/io.c:555 Seagate#10 0x00007f432b7658e1 in be_io_cb (link=0x7f4288001040) at be/io.c:587 Seagate#11 0x00007f432b8a53a0 in clink_signal (clink=0x7f4288001040) at lib/chan.c:135 Seagate#12 0x00007f432b8a54ff in chan_signal_nr (chan=0x7f4288000f38, nr=0) at lib/chan.c:154 Seagate#13 0x00007f432b8a55d4 in m0_chan_broadcast (chan=0x7f4288000f38) at lib/chan.c:174 Seagate#14 0x00007f432b8a55fa in m0_chan_broadcast_lock (chan=0x7f4288000f38) at lib/chan.c:181 Seagate#15 0x00007f432ba03cfe in ioq_complete (ioq=0x1367bc0, qev=0x7f42886a3fe0, res=8, res2=0) at stob/ioq.c:587 Seagate#16 0x00007f432ba041d1 in stob_ioq_thread (ioq=0x1367bc0) at stob/ioq.c:669 Seagate#17 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x1367be0) at lib/thread.c:117 Seagate#18 0x00007f432b8c37fc in uthread_trampoline (arg=0x1367be0) at lib/user_space/uthread.c:98 Seagate#19 0x00007f432af51e25 in start_thread (arg=0x7f42ccff9700) at pthread_create.c:308 Seagate#20 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 (gdb) thread 2 [Switching to thread 2 (Thread 0x7f428ffff700 (LWP 8730))] #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 253 if (!M0_CHECK_EX(m0_tlink_invariant(d, amb(d, scan)))) (gdb) bt #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 Seagate#1 0x00007f432b8b1f13 in m0_tlist_add (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, obj=0x7f42880008c0) at lib/tlist.c:128 Seagate#2 0x00007f432b7664c8 in sched_io_tlist_add (list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, amb=0x7f42880008c0) at be/io_sched.c:48 Seagate#3 0x00007f432b766d88 in be_io_sched_insert (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0) at be/io_sched.c:161 Seagate#4 0x00007f432b767144 in m0_be_io_sched_add (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0, ext=0x7f428fffed00, op=0x7f4288000c00) at be/io_sched.c:193 Seagate#5 0x00007f432cf8a008 in be_ut_io_sched_thread (param=0x136a2b0) at be/ut/io_sched.c:241 Seagate#6 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x136bad0) at lib/thread.c:117 Seagate#7 0x00007f432b8c37fc in uthread_trampoline (arg=0x136bad0) at lib/user_space/uthread.c:98 Seagate#8 0x00007f432af51e25 in start_thread (arg=0x7f428ffff700) at pthread_create.c:308 Seagate#9 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 Signed-off-by: Maksym Medvied <maksym.medvied@seagate.com>

It was possible for the op, passed to m0_be_io_sched_add(), to become DONE before sched lock is taken in be_io_sched_cb() because parent op could become DONE before the child op M0_BTS_GC callback is called. This situation led to failed invariant, assertion failures [1] or just spinning in infinite loop in m0_list invariant due to a broken list [2]. The patch fixes the issue by moving the op (passed to m0_be_io_sched_add()) to DONE only after finishing processing of the corresponding m0_be_io. The bug was discovered during EOS-25005 patch testing. [1] be-ut io_sched motr[15961]: e4b0 FATAL [lib/assert.c:50:m0_panic] panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() (be/io_sched.c:132) [git: 2.0.0-307-37-gd35074f6-dirty] /w/var/m0ut/m0trace.15961 Motr panic: (io->bio_ext.e_start == sched->bis_pos) at be_io_sched_cb() be/io_sched.c:132 (errno: 0) (last failed: none) [git: 2.0.0-307-37-gd35074f6-dirty] pid: 15961 /w/var/m0ut/m0trace.15961 ... [2] (gdb) bt #0 __lll_lock_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/lowlevellock.S:135 #1 0x00007f432af53e1b in _L_lock_812 () from /lib64/libpthread.so.0 #2 0x00007f432af53ce8 in __GI___pthread_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at ../nptl/pthread_mutex_lock.c:79 #3 0x00007f432b8c3520 in m0_arch_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/user_space/umutex.c:56 #4 0x00007f432b8aee6f in m0_mutex_lock (mutex=0x7f432d714a80 <be_ut_io_sched_scheduler+32>) at lib/mutex.c:55 #5 0x00007f432b76673b in m0_be_io_sched_lock (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>) at be/io_sched.c:72 #6 0x00007f432b766a75 in be_io_sched_cb (op=0x7f4288000998, param=0x7f42880008c0) at be/io_sched.c:123 #7 0x00007f432b771bb3 in be_op_done (op=0x7f4288000998) at be/op.c:257 #8 0x00007f432b771cb6 in m0_be_op_done (op=0x7f4288000998) at be/op.c:276 #9 0x00007f432b765715 in be_io_finished (bio=0x7f42880008c0) at be/io.c:555 #10 0x00007f432b7658e1 in be_io_cb (link=0x7f4288001040) at be/io.c:587 #11 0x00007f432b8a53a0 in clink_signal (clink=0x7f4288001040) at lib/chan.c:135 #12 0x00007f432b8a54ff in chan_signal_nr (chan=0x7f4288000f38, nr=0) at lib/chan.c:154 #13 0x00007f432b8a55d4 in m0_chan_broadcast (chan=0x7f4288000f38) at lib/chan.c:174 #14 0x00007f432b8a55fa in m0_chan_broadcast_lock (chan=0x7f4288000f38) at lib/chan.c:181 #15 0x00007f432ba03cfe in ioq_complete (ioq=0x1367bc0, qev=0x7f42886a3fe0, res=8, res2=0) at stob/ioq.c:587 #16 0x00007f432ba041d1 in stob_ioq_thread (ioq=0x1367bc0) at stob/ioq.c:669 #17 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x1367be0) at lib/thread.c:117 #18 0x00007f432b8c37fc in uthread_trampoline (arg=0x1367be0) at lib/user_space/uthread.c:98 #19 0x00007f432af51e25 in start_thread (arg=0x7f42ccff9700) at pthread_create.c:308 #20 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 (gdb) thread 2 [Switching to thread 2 (Thread 0x7f428ffff700 (LWP 8730))] #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 253 if (!M0_CHECK_EX(m0_tlink_invariant(d, amb(d, scan)))) (gdb) bt #0 0x00007f432b8b270b in m0_tlist_invariant (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>) at lib/tlist.c:253 #1 0x00007f432b8b1f13 in m0_tlist_add (d=0x7f432bd94600 <sched_io_tl>, list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, obj=0x7f42880008c0) at lib/tlist.c:128 #2 0x00007f432b7664c8 in sched_io_tlist_add (list=0x7f432d714a68 <be_ut_io_sched_scheduler+8>, amb=0x7f42880008c0) at be/io_sched.c:48 #3 0x00007f432b766d88 in be_io_sched_insert (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0) at be/io_sched.c:161 #4 0x00007f432b767144 in m0_be_io_sched_add (sched=0x7f432d714a60 <be_ut_io_sched_scheduler>, io=0x7f42880008c0, ext=0x7f428fffed00, op=0x7f4288000c00) at be/io_sched.c:193 #5 0x00007f432cf8a008 in be_ut_io_sched_thread (param=0x136a2b0) at be/ut/io_sched.c:241 #6 0x00007f432b8b01b8 in m0_thread_trampoline (arg=0x136bad0) at lib/thread.c:117 #7 0x00007f432b8c37fc in uthread_trampoline (arg=0x136bad0) at lib/user_space/uthread.c:98 #8 0x00007f432af51e25 in start_thread (arg=0x7f428ffff700) at pthread_create.c:308 #9 0x00007f4329999bad in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:113 Signed-off-by: Maksym Medvied <maksym.medvied@seagate.com>

All m0d-ios processes may crash if some of them is crashed during write i/o. Here is the scenario, for example: setup: 1 node, 5 ios processes configured with 2 disks each. 1) Start write: m0cp -l <local-endpoint> -H <hax-endpoint> -p <profile-fid> -P <process-fid> -s 32k -c 1024 -L 2 /dev/zero -o 0x12345678:0x678900202 2) After about 5 secs (to allow m0_client_init() to finish and start the i/o) kill -9 <PID> one of m0d-ios processes. Panic msg: `((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393)` Stack: Seagate#3 0x00007f9454ccbe37 in m0_panic (ctx=ctx@entry=0x7f94550e15a0 <__pctx.8664>) at lib/assert.c:52 Seagate#4 0x00007f9454c0747c in btree_save (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, val=val@entry=0x7f944ca77e70, anchor=0x0, optype=BTREE_SAVE_UPDATE, zonemask=2, key=<optimized out>, key=<optimized out>) at be/btree.c:339 Seagate#5 0x00007f9454c086f7 in m0_be_btree_update (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, key=key@entry=0x7f944ca77e60, val=val@entry=0x7f944ca77e70) at be/btree.c:1952 Seagate#6 0x00007f9454bfd62b in btree_update_sync (val=0x7f944ca77e70, key=0x7f944ca77e60, tx=0x7f94200a7f90, tree=0x40000010ed80) at balloc/balloc.c:95 Seagate#7 balloc_gi_sync (cb=cb@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, gi=gi@entry=0x13ff860) at balloc/balloc.c:928 Seagate#8 0x00007f9454bfe36e in balloc_free_db_update (motr=motr@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, grp=grp@entry=0x13ff860, tgt=tgt@entry=0x7f944ca78470, alloc_flag=<optimized out>) at balloc/balloc.c:1934 Seagate#9 0x00007f9454bff9c6 in balloc_free_internal (req=<synthetic pointer>, req=<synthetic pointer>, tx=0x7f94200a7f90, ctx=0x40000010eb40) at balloc/balloc.c:2716 Seagate#10 balloc_free (ballroom=0x40000010ec68, tx=0x7f94200a7f88, ext=0x7f944ca78560) at balloc/balloc.c:2929 Seagate#11 0x00007f9454d97681 in stob_ad_bfree (adom=<optimized out>, adom=<optimized out>, ext=0x7f944ca78530, ext=0x7f944ca78530, tx=0x7f94200a7f88) at stob/ad.c:1098 Seagate#12 stob_ad_seg_free (tx=0x7f94200a7f88, adom=<optimized out>, ext=ext@entry=0x7f944ca79160, val=1594, seg=<optimized out>) at stob/ad.c:1647 Seagate#13 0x00007f9454d9783d in __lambda (seg=0x7f944ca79150) at stob/ad.c:1719 Seagate#14 0x00007f9454c10802 in m0_be_emap_paste (it=it@entry=0x7f944ca79140, tx=0x7f94200a7f90, ext=ext@entry=0x7f944ca78a90, val=1794, del=del@entry=0x7f944ca78b1c, cut_left=cut_left@entry=0x7f944ca78b38, cut_right=0x7f944ca78b54) at be/extmap.c:628 Seagate#15 0x00007f9454d9a546 in stob_ad_write_map_ext (orig=<optimized out>, off=464, adom=0x4000001120d8) at stob/ad.c:1731 Seagate#16 stob_ad_write_map (map=0x7f944ca78900, frags=18, wc=0x7f944ca78920, dst=0x7f944ca789b0, adom=0x4000001120d8, io=0x7f94340b4298) at stob/ad.c:1858 Seagate#17 stob_ad_write_prepare (map=0x7f944ca78900, src=0x7f944ca78970, adom=0x4000001120d8, io=<optimized out>) at stob/ad.c:2006 Seagate#18 stob_ad_io_launch_prepare (io=<optimized out>) at stob/ad.c:2052 Seagate#19 0x00007f9454d9ca47 in m0_stob_io_prepare (io=io@entry=0x7f94340b4298, obj=obj@entry=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:178 Seagate#20 0x00007f9454d9ce92 in m0_stob_io_prepare_and_launch (io=io@entry=0x7f94340b4298, obj=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:226 Seagate#21 0x00007f9454cb702c in io_launch (fom=0x7f94200a7ec0) at ioservice/io_foms.c:1837 Seagate#22 0x00007f9454cb47a0 in m0_io_fom_cob_rw_tick (fom=0x7f94200a7ec0) at ioservice/io_foms.c:2333 Seagate#23 0x00007f9454c9edf1 in fom_exec (fom=0x7f94200a7ec0) at fop/fom.c:791 Seagate#24 loc_handler_thread (th=0x11ed150) at fop/fom.c:931 RCA: the regression of BE credit calculation in stob/ad.c:stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the change in stob/ad.c:stob_ad_write_credit() introduced at commit ab22d23. Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

Panic: ((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393) Stack: Seagate#3 0x00007f9454ccbe37 in m0_panic (ctx=ctx@entry=0x7f94550e15a0 <__pctx.8664>) at lib/assert.c:52 Seagate#4 0x00007f9454c0747c in btree_save (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, val=val@entry=0x7f944ca77e70, anchor=0x0, optype=BTREE_SAVE_UPDATE, zonemask=2, key=<optimized out>, key=<optimized out>) at be/btree.c:339 Seagate#5 0x00007f9454c086f7 in m0_be_btree_update (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, key=key@entry=0x7f944ca77e60, val=val@entry=0x7f944ca77e70) at be/btree.c:1952 Seagate#6 0x00007f9454bfd62b in btree_update_sync (val=0x7f944ca77e70, key=0x7f944ca77e60, tx=0x7f94200a7f90, tree=0x40000010ed80) at balloc/balloc.c:95 Seagate#7 balloc_gi_sync (cb=cb@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, gi=gi@entry=0x13ff860) at balloc/balloc.c:928 Seagate#8 0x00007f9454bfe36e in balloc_free_db_update (motr=motr@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, grp=grp@entry=0x13ff860, tgt=tgt@entry=0x7f944ca78470, alloc_flag=<optimized out>) at balloc/balloc.c:1934 Seagate#9 0x00007f9454bff9c6 in balloc_free_internal (req=<synthetic pointer>, req=<synthetic pointer>, tx=0x7f94200a7f90, ctx=0x40000010eb40) at balloc/balloc.c:2716 Seagate#10 balloc_free (ballroom=0x40000010ec68, tx=0x7f94200a7f88, ext=0x7f944ca78560) at balloc/balloc.c:2929 Seagate#11 0x00007f9454d97681 in stob_ad_bfree (adom=<optimized out>, adom=<optimized out>, ext=0x7f944ca78530, ext=0x7f944ca78530, tx=0x7f94200a7f88) at stob/ad.c:1098 Seagate#12 stob_ad_seg_free (tx=0x7f94200a7f88, adom=<optimized out>, ext=ext@entry=0x7f944ca79160, val=1594, seg=<optimized out>) at stob/ad.c:1647 Seagate#13 0x00007f9454d9783d in __lambda (seg=0x7f944ca79150) at stob/ad.c:1719 Seagate#14 0x00007f9454c10802 in m0_be_emap_paste (it=it@entry=0x7f944ca79140, tx=0x7f94200a7f90, ext=ext@entry=0x7f944ca78a90, val=1794, del=del@entry=0x7f944ca78b1c, cut_left=cut_left@entry=0x7f944ca78b38, cut_right=0x7f944ca78b54) at be/extmap.c:628 Seagate#15 0x00007f9454d9a546 in stob_ad_write_map_ext (orig=<optimized out>, off=464, adom=0x4000001120d8) at stob/ad.c:1731 Seagate#16 stob_ad_write_map (map=0x7f944ca78900, frags=18, wc=0x7f944ca78920, dst=0x7f944ca789b0, adom=0x4000001120d8, io=0x7f94340b4298) at stob/ad.c:1858 Seagate#17 stob_ad_write_prepare (map=0x7f944ca78900, src=0x7f944ca78970, adom=0x4000001120d8, io=<optimized out>) at stob/ad.c:2006 Seagate#18 stob_ad_io_launch_prepare (io=<optimized out>) at stob/ad.c:2052 Seagate#19 0x00007f9454d9ca47 in m0_stob_io_prepare (io=io@entry=0x7f94340b4298, obj=obj@entry=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:178 Seagate#20 0x00007f9454d9ce92 in m0_stob_io_prepare_and_launch (io=io@entry=0x7f94340b4298, obj=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:226 Seagate#21 0x00007f9454cb702c in io_launch (fom=0x7f94200a7ec0) at ioservice/io_foms.c:1837 Seagate#22 0x00007f9454cb47a0 in m0_io_fom_cob_rw_tick (fom=0x7f94200a7ec0) at ioservice/io_foms.c:2333 Seagate#23 0x00007f9454c9edf1 in fom_exec (fom=0x7f94200a7ec0) at fop/fom.c:791 Seagate#24 loc_handler_thread (th=0x11ed150) at fop/fom.c:931 Setup: 1-node, 5 ios processes configured with 2 disks each, 4+2+0 EC data pool. Scenario: write the same object twice like this: $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 -u RCA: regression of BE credit calculation in stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the regression change. Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

Panic: ((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393) Stack: Seagate#3 0x00007f9454ccbe37 in m0_panic (ctx=ctx@entry=0x7f94550e15a0 <__pctx.8664>) at lib/assert.c:52 Seagate#4 0x00007f9454c0747c in btree_save (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, val=val@entry=0x7f944ca77e70, anchor=0x0, optype=BTREE_SAVE_UPDATE, zonemask=2, key=<optimized out>, key=<optimized out>) at be/btree.c:339 Seagate#5 0x00007f9454c086f7 in m0_be_btree_update (tree=tree@entry=0x40000010ed80, tx=tx@entry=0x7f94200a7f90, op=op@entry=0x7f944ca77ec0, key=key@entry=0x7f944ca77e60, val=val@entry=0x7f944ca77e70) at be/btree.c:1952 Seagate#6 0x00007f9454bfd62b in btree_update_sync (val=0x7f944ca77e70, key=0x7f944ca77e60, tx=0x7f94200a7f90, tree=0x40000010ed80) at balloc/balloc.c:95 Seagate#7 balloc_gi_sync (cb=cb@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, gi=gi@entry=0x13ff860) at balloc/balloc.c:928 Seagate#8 0x00007f9454bfe36e in balloc_free_db_update (motr=motr@entry=0x40000010eb40, tx=tx@entry=0x7f94200a7f90, grp=grp@entry=0x13ff860, tgt=tgt@entry=0x7f944ca78470, alloc_flag=<optimized out>) at balloc/balloc.c:1934 Seagate#9 0x00007f9454bff9c6 in balloc_free_internal (req=<synthetic pointer>, req=<synthetic pointer>, tx=0x7f94200a7f90, ctx=0x40000010eb40) at balloc/balloc.c:2716 Seagate#10 balloc_free (ballroom=0x40000010ec68, tx=0x7f94200a7f88, ext=0x7f944ca78560) at balloc/balloc.c:2929 Seagate#11 0x00007f9454d97681 in stob_ad_bfree (adom=<optimized out>, adom=<optimized out>, ext=0x7f944ca78530, ext=0x7f944ca78530, tx=0x7f94200a7f88) at stob/ad.c:1098 Seagate#12 stob_ad_seg_free (tx=0x7f94200a7f88, adom=<optimized out>, ext=ext@entry=0x7f944ca79160, val=1594, seg=<optimized out>) at stob/ad.c:1647 Seagate#13 0x00007f9454d9783d in __lambda (seg=0x7f944ca79150) at stob/ad.c:1719 Seagate#14 0x00007f9454c10802 in m0_be_emap_paste (it=it@entry=0x7f944ca79140, tx=0x7f94200a7f90, ext=ext@entry=0x7f944ca78a90, val=1794, del=del@entry=0x7f944ca78b1c, cut_left=cut_left@entry=0x7f944ca78b38, cut_right=0x7f944ca78b54) at be/extmap.c:628 Seagate#15 0x00007f9454d9a546 in stob_ad_write_map_ext (orig=<optimized out>, off=464, adom=0x4000001120d8) at stob/ad.c:1731 Seagate#16 stob_ad_write_map (map=0x7f944ca78900, frags=18, wc=0x7f944ca78920, dst=0x7f944ca789b0, adom=0x4000001120d8, io=0x7f94340b4298) at stob/ad.c:1858 Seagate#17 stob_ad_write_prepare (map=0x7f944ca78900, src=0x7f944ca78970, adom=0x4000001120d8, io=<optimized out>) at stob/ad.c:2006 Seagate#18 stob_ad_io_launch_prepare (io=<optimized out>) at stob/ad.c:2052 Seagate#19 0x00007f9454d9ca47 in m0_stob_io_prepare (io=io@entry=0x7f94340b4298, obj=obj@entry=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:178 Seagate#20 0x00007f9454d9ce92 in m0_stob_io_prepare_and_launch (io=io@entry=0x7f94340b4298, obj=0x7f94341170a0, tx=tx@entry=0x7f94200a7f88, scope=scope@entry=0x0) at stob/io.c:226 Seagate#21 0x00007f9454cb702c in io_launch (fom=0x7f94200a7ec0) at ioservice/io_foms.c:1837 Seagate#22 0x00007f9454cb47a0 in m0_io_fom_cob_rw_tick (fom=0x7f94200a7ec0) at ioservice/io_foms.c:2333 Seagate#23 0x00007f9454c9edf1 in fom_exec (fom=0x7f94200a7ec0) at fop/fom.c:791 Seagate#24 loc_handler_thread (th=0x11ed150) at fop/fom.c:931 Setup: 1-node, 4+2+0 EC data pool with 10 disks. Scenario: write the same object twice like this: $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 -u RCA: regression of BE credit calculation in stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the regression change. Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

Panic: ((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393) Stack: Seagate#3 m0_panic() at lib/assert.c:52 Seagate#4 btree_save() at be/btree.c:339 Seagate#5 m0_be_btree_update() at be/btree.c:1952 Seagate#6 btree_update_sync() at balloc/balloc.c:95 Seagate#7 balloc_gi_sync() at balloc/balloc.c:928 Seagate#8 balloc_free_db_update() at balloc/balloc.c:1934 Seagate#9 balloc_free_internal() at balloc/balloc.c:2716 Seagate#10 balloc_free() at balloc/balloc.c:2929 Seagate#11 stob_ad_bfree() at stob/ad.c:1098 Seagate#12 stob_ad_seg_free (val=1594) at stob/ad.c:1647 Seagate#13 __lambda() at stob/ad.c:1719 Seagate#14 m0_be_emap_paste(val=1794) at be/extmap.c:628 Seagate#15 stob_ad_write_map_ext(off=464) at stob/ad.c:1731 Seagate#16 stob_ad_write_map(frags=18) at stob/ad.c:1858 Seagate#17 stob_ad_write_prepare() at stob/ad.c:2006 Seagate#18 stob_ad_io_launch_prepare() at stob/ad.c:2052 Seagate#19 m0_stob_io_prepare() at stob/io.c:178 Seagate#20 m0_stob_io_prepare_and_launch() at stob/io.c:226 Seagate#21 io_launch() at ioservice/io_foms.c:1837 Seagate#22 m0_io_fom_cob_rw_tick() at ioservice/io_foms.c:2333 Seagate#23 fom_exec() at fop/fom.c:791 Seagate#24 loc_handler_thread() at fop/fom.c:931 Setup: 1 node, 4+2+0 EC data pool with 10 disks. Scenario: write the same object twice like this: $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 -u RCA: regression of BE credit calculation in stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the regression change. Co-authored-by: Madhavrao Vemuri <madhav.vemuri@seagate.com> Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

Problem: Following panic occurs if update operation is done, Panic: ((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393) Stack: #3 m0_panic() at lib/assert.c:52 #4 btree_save() at be/btree.c:339 #5 m0_be_btree_update() at be/btree.c:1952 #6 btree_update_sync() at balloc/balloc.c:95 #7 balloc_gi_sync() at balloc/balloc.c:928 #8 balloc_free_db_update() at balloc/balloc.c:1934 #9 balloc_free_internal() at balloc/balloc.c:2716 #10 balloc_free() at balloc/balloc.c:2929 #11 stob_ad_bfree() at stob/ad.c:1098 #12 stob_ad_seg_free (val=1594) at stob/ad.c:1647 #13 __lambda() at stob/ad.c:1719 #14 m0_be_emap_paste(val=1794) at be/extmap.c:628 #15 stob_ad_write_map_ext(off=464) at stob/ad.c:1731 #16 stob_ad_write_map(frags=18) at stob/ad.c:1858 #17 stob_ad_write_prepare() at stob/ad.c:2006 #18 stob_ad_io_launch_prepare() at stob/ad.c:2052 #19 m0_stob_io_prepare() at stob/io.c:178 #20 m0_stob_io_prepare_and_launch() at stob/io.c:226 #21 io_launch() at ioservice/io_foms.c:1837 #22 m0_io_fom_cob_rw_tick() at ioservice/io_foms.c:2333 #23 fom_exec() at fop/fom.c:791 #24 loc_handler_thread() at fop/fom.c:931 Setup: 1 node, 4+2+0 EC data pool with 10 disks. Scenario: write the same object twice like this: $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 -u RCA: regression of BE credit calculation in stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the regression change. Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

Panic: ((cr->tc_balance[cu]) != 0) at btree_save() (be/btree.c:1393) Stack: Seagate#3 m0_panic() at lib/assert.c:52 Seagate#4 btree_save() at be/btree.c:339 Seagate#5 m0_be_btree_update() at be/btree.c:1952 Seagate#6 btree_update_sync() at balloc/balloc.c:95 Seagate#7 balloc_gi_sync() at balloc/balloc.c:928 Seagate#8 balloc_free_db_update() at balloc/balloc.c:1934 Seagate#9 balloc_free_internal() at balloc/balloc.c:2716 Seagate#10 balloc_free() at balloc/balloc.c:2929 Seagate#11 stob_ad_bfree() at stob/ad.c:1098 Seagate#12 stob_ad_seg_free (val=1594) at stob/ad.c:1647 Seagate#13 __lambda() at stob/ad.c:1719 Seagate#14 m0_be_emap_paste(val=1794) at be/extmap.c:628 Seagate#15 stob_ad_write_map_ext(off=464) at stob/ad.c:1731 Seagate#16 stob_ad_write_map(frags=18) at stob/ad.c:1858 Seagate#17 stob_ad_write_prepare() at stob/ad.c:2006 Seagate#18 stob_ad_io_launch_prepare() at stob/ad.c:2052 Seagate#19 m0_stob_io_prepare() at stob/io.c:178 Seagate#20 m0_stob_io_prepare_and_launch() at stob/io.c:226 Seagate#21 io_launch() at ioservice/io_foms.c:1837 Seagate#22 m0_io_fom_cob_rw_tick() at ioservice/io_foms.c:2333 Seagate#23 fom_exec() at fop/fom.c:791 Seagate#24 loc_handler_thread() at fop/fom.c:931 Setup: 1 node, 4+2+0 EC data pool with 10 disks. Scenario: write the same object twice like this: $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 $ m0cp <motr-conn-params> -s 1m -c 40 -L 4 /dev/zero -o 0x12345678:0x678900207 -u RCA: regression of BE credit calculation in stob_ad_write_credit() code was introduced at commit ab22d23. Solution: rollback the regression change. Co-authored-by: Madhavrao Vemuri <madhav.vemuri@seagate.com> Signed-off-by: Andriy Tkachuk <andriy.tkachuk@seagate.com>

… gc callback of (#1820) Problem : In m0_be_op_fini, when bos_tlink_fini is performed then its expected that bo_set_link should not have link for link for parent's m0_be_op::bo_children. State seen at the time of crash: Two gft_pd_io in progress state, with corresponding two bio in sched queue; crash is hit while performing the gc callback processing for gft whhose gft_pd_io is in progress state and bio is queued behind an active io. Panic: 2022-04-24 11:19:15,672 - motr[00107]: e2e0 FATAL [lib/assert.c:50:m0_panic] panic: (!m0_list_link_is_in(link)) at m0_list_link_fini() (lib/list.c:178) [git: 2.0.0-670-27-g0012fe90] /etc/cortx/log/motr/0696b1d9e4744c59a92cb2bdded112ac/trace/m0d-0x7200000000000001:0x2e/m0trace.107 2022-04-24 11:19:15,672 - Motr panic: (!m0_list_link_is_in(link)) at m0_list_link_fini() lib/list.c:178 (errno: 0) (last failed: none) [git: 2.0.0-670-27-g0012fe90] pid: 107 /etc/cortx/log/motr/0696b1d9e4744c59a92cb2bdded112ac/trace/m0d-0x7200000000000001:0x2e/m0trace.107 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_arch_backtrace+0x33)[0x7f7514e79c83] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_arch_panic+0xe9)[0x7f7514e79e59] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_panic+0x13d)[0x7f7514e6890d] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(+0x3895f6)[0x7f7514e6c5f6] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_be_op_fini+0x1f)[0x7f7514dae66f] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(+0x2cb826)[0x7f7514dae826] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c4c5b)[0x7f7514da7c5b] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2cb826)[0x7f7514dae826] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c300a)[0x7f7514da600a] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c3119)[0x7f7514da6119] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x386f7f)[0x7f7514e69f7f] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x386ffa)[0x7f7514e69ffa] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(m0_chan_broadcast_lock+0x1d)[0x7f7514e6a08d] Backtrace: (gdb) bt #0 0x00007f7512d8938f in raise () from /lib64/libc.so.6 #1 0x00007f7512d73dc5 in abort () from /lib64/libc.so.6 #2 0x00007f7514e79e63 in m0_arch_panic (c=c@entry=0x7f751531ade0 <__pctx.4611>, ap=ap@entry=0x7f74afffe390) at lib/user_space/uassert.c:131 #3 0x00007f7514e6890d in m0_panic (ctx=ctx@entry=0x7f751531ade0 <__pctx.4611>) at lib/assert.c:52 #4 0x00007f7514e6c5f6 in m0_list_link_fini (link=) at lib/list.c:178 #5 0x00007f7514e70310 in m0_tlink_fini (d=d@entry=0x7f75152880a0 <bos_tl>, obj=obj@entry=0x56523e641a90) at lib/tlist.c:283 #6 0x00007f7514dae66f in bos_tlink_fini (amb=0x56523e641a90) at be/op.c:109 #7 m0_be_op_fini (op=0x56523e641a90) at be/op.c:109 #8 0x00007f7514dae826 in be_op_state_change (op=, state=state@entry=M0_BOS_DONE) at be/op.c:213 #9 0x00007f7514daea17 in m0_be_op_done (op=) at be/op.c:231 #10 0x00007f7514da7c5b in be_io_sched_cb (op=op@entry=0x56523e5f7870, param=param@entry=0x56523e5f7798) at be/io_sched.c:141 #11 0x00007f7514dae826 in be_op_state_change (op=op@entry=0x56523e5f7870, state=state@entry=M0_BOS_DONE) at be/op.c:213 #12 0x00007f7514daea17 in m0_be_op_done (op=op@entry=0x56523e5f7870) at be/op.c:231 #13 0x00007f7514da600a in be_io_finished (bio=bio@entry=0x56523e5f7798) at be/io.c:555 #14 0x00007f7514da6119 in be_io_cb (link=0x56523e61ac60) at be/io.c:587 #15 0x00007f7514e69f7f in clink_signal (clink=clink@entry=0x56523e61ac60) at lib/chan.c:135 #16 0x00007f7514e69ffa in chan_signal_nr (chan=chan@entry=0x56523e61ab58, nr=0) at lib/chan.c:154 #17 0x00007f7514e6a06c in m0_chan_broadcast (chan=chan@entry=0x56523e61ab58) at lib/chan.c:174 #18 0x00007f7514e6a08d in m0_chan_broadcast_lock (chan=chan@entry=0x56523e61ab58) at lib/chan.c:181 #19 0x00007f7514f4209a in ioq_complete (res2=, res=, qev=, ioq=0x56523e5de610) at stob/ioq.c:587 #20 stob_ioq_thread (ioq=0x56523e5de610) at stob/ioq.c:669 #21 0x00007f7514e6f49e in m0_thread_trampoline (arg=arg@entry=0x56523e5de6e8) at lib/thread.c:117 #22 0x00007f7514e7ab11 in uthread_trampoline (arg=0x56523e5de6e8) at lib/user_space/uthread.c:98 #23 0x00007f751454915a in start_thread () from /lib64/libpthread.so.0 #24 0x00007f7512e4edd3 in clone () from /lib64/libc.so.6 RCA - Sequence of Events: be_tx_group_format_seg_io_op_gc invoked for gft_pd_io_op of tx_group_fom_1 (last_child is false) (gdb) p &((struct m0_be_group_format *)cb_gc_param)->gft_pd_io_op $29 = (struct m0_be_op *) 0x56523e641a90 be_tx_group_format_seg_io_op_gc handling of gft_pd_io_op invokes m0_be_op_done for gft_tmp_op (no callbacks for gft_tmp_op) but now last_child is set true for parent as its both child (gft_tmp_op and gft_pd_io_op) op dones have been invoked m0_be_op_done handling of gft_tmp_op invokes be_op_state_change with M0_BOS_DONE for parent(tgf_op) During be_op_state_change processing for main parent tgf_op, m0_sm_state_set will update bo_sm state and it will unblock the tx_group_fom_1 by triggering op->bo_sm.sm_chan This recursive callback processing happens in context of stob_ioq_thread which is initialized on M0_STOB_IOQ_NR_THREADS. Here due to invocation of gft_tmp_op (i.e peer) child done processing from gft_pd_io_op child gc processing results in their parent early callback invocation. Parent Callback Prcoseeing: 6. This now unblocks tx_group_fom_1 which will lead to m0_be_pd_io_put in m0_be_group_format_reset and and tx_group_fom_1 will move to TGS_OPEN. So pd_io and tx_group_fom_1 is now ready for reuse. Problem window: 7. problem will now occur in window if remaining gc callback processing of gft_pd_io_op i.e. m0_be_op_fini(&gft->gft_tmp_op); m0_be_op_fini(op); is being done if the pd_io and/or tx_group_fom_1 is reused with new context. Solution: Removal of gft_tmp_op altogether will ensure that parent callback processing never invoked ahead of its child callback processing This way tx_group_fom will always be notifed of seg io completion only after all the relevent child calbback processing is completed and thereby will avoid the crashes seen in the gc callback processing(be_tx_group_format_seg_io_op_gc) after m0_be_op_done(&gft->gft_tmp_op); In proposed solution main parent op is made active at the start at the same place where gft_tmp_op was being activated in order to put this parent into active state; there by making gft_tmp_op redundent and avoiding the out of order execution of child/parent callback executions; RCA: Due to recursive calls to be_op_state_change where gc callback of gft_op i.e. child1 invokes done callback of gft_tmp_op i.e. child 2 which subsequently results in invocation of parent be_op_state_change. This results in group fom getting completed ahead of child op callback processing. so the subsequently crash is observed when group is reused before child callback processing is finished. Signed-off-by: Vidyadhar Pinglikar vidyadhar.pinglikar@seagate.com

… gc callback of (Seagate#1820) Problem : In m0_be_op_fini, when bos_tlink_fini is performed then its expected that bo_set_link should not have link for link for parent's m0_be_op::bo_children. State seen at the time of crash: Two gft_pd_io in progress state, with corresponding two bio in sched queue; crash is hit while performing the gc callback processing for gft whhose gft_pd_io is in progress state and bio is queued behind an active io. Panic: 2022-04-24 11:19:15,672 - motr[00107]: e2e0 FATAL [lib/assert.c:50:m0_panic] panic: (!m0_list_link_is_in(link)) at m0_list_link_fini() (lib/list.c:178) [git: 2.0.0-670-27-g0012fe90] /etc/cortx/log/motr/0696b1d9e4744c59a92cb2bdded112ac/trace/m0d-0x7200000000000001:0x2e/m0trace.107 2022-04-24 11:19:15,672 - Motr panic: (!m0_list_link_is_in(link)) at m0_list_link_fini() lib/list.c:178 (errno: 0) (last failed: none) [git: 2.0.0-670-27-g0012fe90] pid: 107 /etc/cortx/log/motr/0696b1d9e4744c59a92cb2bdded112ac/trace/m0d-0x7200000000000001:0x2e/m0trace.107 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_arch_backtrace+0x33)[0x7f7514e79c83] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_arch_panic+0xe9)[0x7f7514e79e59] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_panic+0x13d)[0x7f7514e6890d] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(+0x3895f6)[0x7f7514e6c5f6] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(m0_be_op_fini+0x1f)[0x7f7514dae66f] 2022-04-24 11:19:15,706 - /lib64/libmotr.so.2(+0x2cb826)[0x7f7514dae826] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c4c5b)[0x7f7514da7c5b] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2cb826)[0x7f7514dae826] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c300a)[0x7f7514da600a] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x2c3119)[0x7f7514da6119] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x386f7f)[0x7f7514e69f7f] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(+0x386ffa)[0x7f7514e69ffa] 2022-04-24 11:19:15,707 - /lib64/libmotr.so.2(m0_chan_broadcast_lock+0x1d)[0x7f7514e6a08d] Backtrace: (gdb) bt #0 0x00007f7512d8938f in raise () from /lib64/libc.so.6 Seagate#1 0x00007f7512d73dc5 in abort () from /lib64/libc.so.6 Seagate#2 0x00007f7514e79e63 in m0_arch_panic (c=c@entry=0x7f751531ade0 <__pctx.4611>, ap=ap@entry=0x7f74afffe390) at lib/user_space/uassert.c:131 Seagate#3 0x00007f7514e6890d in m0_panic (ctx=ctx@entry=0x7f751531ade0 <__pctx.4611>) at lib/assert.c:52 Seagate#4 0x00007f7514e6c5f6 in m0_list_link_fini (link=) at lib/list.c:178 Seagate#5 0x00007f7514e70310 in m0_tlink_fini (d=d@entry=0x7f75152880a0 <bos_tl>, obj=obj@entry=0x56523e641a90) at lib/tlist.c:283 Seagate#6 0x00007f7514dae66f in bos_tlink_fini (amb=0x56523e641a90) at be/op.c:109 Seagate#7 m0_be_op_fini (op=0x56523e641a90) at be/op.c:109 Seagate#8 0x00007f7514dae826 in be_op_state_change (op=, state=state@entry=M0_BOS_DONE) at be/op.c:213 Seagate#9 0x00007f7514daea17 in m0_be_op_done (op=) at be/op.c:231 Seagate#10 0x00007f7514da7c5b in be_io_sched_cb (op=op@entry=0x56523e5f7870, param=param@entry=0x56523e5f7798) at be/io_sched.c:141 Seagate#11 0x00007f7514dae826 in be_op_state_change (op=op@entry=0x56523e5f7870, state=state@entry=M0_BOS_DONE) at be/op.c:213 Seagate#12 0x00007f7514daea17 in m0_be_op_done (op=op@entry=0x56523e5f7870) at be/op.c:231 Seagate#13 0x00007f7514da600a in be_io_finished (bio=bio@entry=0x56523e5f7798) at be/io.c:555 Seagate#14 0x00007f7514da6119 in be_io_cb (link=0x56523e61ac60) at be/io.c:587 Seagate#15 0x00007f7514e69f7f in clink_signal (clink=clink@entry=0x56523e61ac60) at lib/chan.c:135 Seagate#16 0x00007f7514e69ffa in chan_signal_nr (chan=chan@entry=0x56523e61ab58, nr=0) at lib/chan.c:154 Seagate#17 0x00007f7514e6a06c in m0_chan_broadcast (chan=chan@entry=0x56523e61ab58) at lib/chan.c:174 Seagate#18 0x00007f7514e6a08d in m0_chan_broadcast_lock (chan=chan@entry=0x56523e61ab58) at lib/chan.c:181 Seagate#19 0x00007f7514f4209a in ioq_complete (res2=, res=, qev=, ioq=0x56523e5de610) at stob/ioq.c:587 Seagate#20 stob_ioq_thread (ioq=0x56523e5de610) at stob/ioq.c:669 Seagate#21 0x00007f7514e6f49e in m0_thread_trampoline (arg=arg@entry=0x56523e5de6e8) at lib/thread.c:117 Seagate#22 0x00007f7514e7ab11 in uthread_trampoline (arg=0x56523e5de6e8) at lib/user_space/uthread.c:98 Seagate#23 0x00007f751454915a in start_thread () from /lib64/libpthread.so.0 Seagate#24 0x00007f7512e4edd3 in clone () from /lib64/libc.so.6 RCA - Sequence of Events: be_tx_group_format_seg_io_op_gc invoked for gft_pd_io_op of tx_group_fom_1 (last_child is false) (gdb) p &((struct m0_be_group_format *)cb_gc_param)->gft_pd_io_op $29 = (struct m0_be_op *) 0x56523e641a90 be_tx_group_format_seg_io_op_gc handling of gft_pd_io_op invokes m0_be_op_done for gft_tmp_op (no callbacks for gft_tmp_op) but now last_child is set true for parent as its both child (gft_tmp_op and gft_pd_io_op) op dones have been invoked m0_be_op_done handling of gft_tmp_op invokes be_op_state_change with M0_BOS_DONE for parent(tgf_op) During be_op_state_change processing for main parent tgf_op, m0_sm_state_set will update bo_sm state and it will unblock the tx_group_fom_1 by triggering op->bo_sm.sm_chan This recursive callback processing happens in context of stob_ioq_thread which is initialized on M0_STOB_IOQ_NR_THREADS. Here due to invocation of gft_tmp_op (i.e peer) child done processing from gft_pd_io_op child gc processing results in their parent early callback invocation. Parent Callback Prcoseeing: 6. This now unblocks tx_group_fom_1 which will lead to m0_be_pd_io_put in m0_be_group_format_reset and and tx_group_fom_1 will move to TGS_OPEN. So pd_io and tx_group_fom_1 is now ready for reuse. Problem window: 7. problem will now occur in window if remaining gc callback processing of gft_pd_io_op i.e. m0_be_op_fini(&gft->gft_tmp_op); m0_be_op_fini(op); is being done if the pd_io and/or tx_group_fom_1 is reused with new context. Solution: Removal of gft_tmp_op altogether will ensure that parent callback processing never invoked ahead of its child callback processing This way tx_group_fom will always be notifed of seg io completion only after all the relevent child calbback processing is completed and thereby will avoid the crashes seen in the gc callback processing(be_tx_group_format_seg_io_op_gc) after m0_be_op_done(&gft->gft_tmp_op); In proposed solution main parent op is made active at the start at the same place where gft_tmp_op was being activated in order to put this parent into active state; there by making gft_tmp_op redundent and avoiding the out of order execution of child/parent callback executions; RCA: Due to recursive calls to be_op_state_change where gc callback of gft_op i.e. child1 invokes done callback of gft_tmp_op i.e. child 2 which subsequently results in invocation of parent be_op_state_change. This results in group fom getting completed ahead of child op callback processing. so the subsequently crash is observed when group is reused before child callback processing is finished. Signed-off-by: Vidyadhar Pinglikar vidyadhar.pinglikar@seagate.com

justinzw assigned VenkyOS Sep 3, 2020

justinzw transferred this issue from Seagate/cortx Sep 3, 2020

stale bot closed this as completed Sep 16, 2020

gauravchaudhari02 reopened this Sep 17, 2020

gauravchaudhari02 transferred this issue from another repository Sep 22, 2020

madhavemuri closed this as completed Sep 22, 2020

madhavemuri mentioned this issue Oct 5, 2020

EOS-13878 scripts: use MOTR_M0D_IOS_BESEG_SIZE for ioservice #88

Merged

max-seagate mentioned this issue Jul 7, 2021

EOS-22127 fdmi/fol_fdmi_src: don't post fdmi record if src dock fom is not running #823

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max-seagate mentioned this issue Sep 29, 2021

EOS-25109 be/io_sched: fix op done ordering bug #1090

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vidyadhar-pinglikar mentioned this issue Jun 7, 2022

CORTX-30993 - BE: Avoid usage of gft_tmp_op to put group fom op into active state #1820

Merged

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cortx-admin mentioned this issue Aug 2, 2022

panic at m0_balloc_load_extents() (balloc/balloc.c:1347) #1845

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Please move a document #18

Please move a document #18

johnbent commented Sep 1, 2020

VenkyOS commented Sep 2, 2020

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VenkyOS commented Sep 22, 2020

Please move a document #18

Please move a document #18

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johnbent commented Sep 1, 2020

VenkyOS commented Sep 2, 2020

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VenkyOS commented Sep 22, 2020